Seed delivery apparatus, systems, and methods

ABSTRACT

An apparatus and methods for delivering seed from a metering device to a furrow. In one embodiment, a seed meter entrains and releases seed from a seed disc at a seed release location. The released seed is directed into a seed conveyor by a loading wheel. The seed conveyor conveys the seed toward the soil and releases the seed with a rearward relative velocity.

BACKGROUND

In recent years, the agricultural industry has recognized the need toperform planting operations more quickly due to the limited time duringwhich such planting operations are agronomically preferable or (in somegrowing seasons) even possible due to inclement weather. However,drawing a planting implement through the field at faster speedsincreases the speed of deposited seeds relative to the ground, causingseeds to roll and bounce upon landing in the trench and resulting ininconsistent plant spacing. The adverse agronomic effects of poor seedplacement and inconsistent plant spacing are well known in the art.

As such, there is a need for apparatus, systems and methods ofeffectively delivering seed to the trench while maintaining seedplacement accuracy at both low and high implement speeds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side elevation view of a prior art row unit of anagricultural row crop planter.

FIG. 2 is a right side elevation view of an embodiment of a row unitincluding a seed conveyor.

FIG. 3 is a right side elevation view of the row unit of FIG. 2 withfurther components removed for illustration purposes.

FIG. 4 is a rear perspective view of the row unit of FIG. 2 with furthercomponents removed for illustration purposes.

FIG. 5 is a left side elevation view of an embodiment of a seed meterand an embodiment of a seed conveyor of the row unit of FIG. 2.

FIG. 6A is an enlarged left side elevation view of an embodiment of alower pulley.

FIG. 6B is an enlarged left side elevation view of another embodiment ofa lower pulley.

FIG. 7 is an enlarged right side elevation view of an embodiment of aloading wheel assembly and an embodiment of a seed disc.

FIG. 8 is an enlarged upward perspective view of the loading wheelassembly of FIG. 7.

FIG. 9 is an enlarged downward perspective view of the loading wheelassembly of FIG. 7.

FIG. 10 is a right side elevation view of the loading wheel assemblyembodiment of FIG. 7 and another embodiment of a seed disc.

FIG. 11 is a right side elevation view of another embodiment of aloading wheel assembly.

FIG. 12 is an enlarged left perspective view of a lower portion of theseed conveyor of FIG. 2.

FIG. 13 is an enlarged right perspective view of a lower portion of theseed conveyor of FIG. 2.

FIG. 14 is an enlarged side elevation view of the loading wheel assemblyembodiment of FIG. 10 and a guide brush assembly.

FIG. 15 is an enlarged rear elevation view of the loading wheel assemblyand guide brush of FIG. 14.

FIG. 16 is a left side elevation view of an embodiment of a row unitincorporating an embodiment of a seed conveyor and an embodiment of aseed meter.

FIG. 17 is a right side elevation view of the row unit of FIG. 16.

FIG. 18 is an enlarged partial right side elevation view of the row unitof FIG. 17.

FIG. 19 is a left side elevation view of a seed side housing of the seedmeter of FIG. 16.

FIG. 20 is a view of a portion of the row unit as viewed along lines20-20 of FIG. 18.

FIG. 21 is an expanded left side elevation view of the row unit of FIG.16 with certain components removed.

FIG. 22 is a front elevation view of an embodiment of a seed conveyorand seed sensor.

FIG. 23 is a side elevation view of an embodiment of a seed conveyorhaving a third pulley.

FIG. 24 is a side elevation view of another embodiment of a loadingwheel assembly having a guide insert.

DESCRIPTION

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIG. 1illustrates a side elevation view of a single row unit 10 of aconventional row crop planter such as the type disclosed in U.S. Pat.No. 7,438,006, the disclosure of which is hereby incorporated herein inits entirety by reference. As is well known in the art, the row units 10are mounted in spaced relation along the length of a transverse toolbar12 by a parallel linkage 14, comprised of upper and lower parallel arms16, 18 pivotally mounted at their forward ends to the transverse toolbar12 and at their rearward end to the row unit frame 20. The parallellinkage 14 permits each row unit 10 to move vertically independently ofthe toolbar 12 and the other spaced row units in order to accommodatechanges in terrain or rocks or other obstructions encountered by the rowunit as the planter is drawn through the field.

The row unit frame 20 operably supports a seed hopper 23 which may beadapted to receive seed from a bulk hopper (not shown), a seed meter 26and a seed tube 28 as well as a furrow opener assembly 30 and furrowclosing assembly 40. The furrow opening assembly 30 comprises a pair offurrow opener discs 32 and a pair of gauge wheels 34. The gauge wheels34 are pivotally secured to the row unit frame 20 by gauge wheel arms36. A coil spring 50 is disposed between the parallel arms 16, 18 toprovide supplemental downforce to ensure that the furrow opener discs 32fully penetrate the soil to the desired depth as set by a depthadjusting member (not shown) and to provide soil compaction for properfurrow formation. Rather than a coil spring, supplemental downforce maybe provided by actuators or other suitable means such as disclosed inU.S. Pat. No. 6,389,999 to Duello, the entire disclosure of which ishereby incorporated herein by reference.

In operation, as the row unit 10 is lowered to the planting position,the opener discs 32 penetrate into the soil. At the same time, the soilforces the gauge wheels 34 to pivot upwardly until the gauge wheel arms36 abut or come into contact with the stop position previously set withthe furrow depth adjusting member (not shown) or until a static loadbalance is achieved between the vertical load of the row unit and thereaction of the soil. As the planter is drawn forwardly in the directionindicated by arrow 39, the furrow opener discs cut a V-shaped furrow 60into the soil while the gauge wheels 34 compact the soil to aid information of the V-shaped furrow. Individual seeds 62 from the seedhopper 23 are dispensed by the seed meter 26 into an upper opening inthe seed tube 28 in uniformly spaced increments. As seeds 62 fallthrough the seed tube 28, the seeds move downwardly and rearwardlybetween the furrow opener discs 32 and into the bottom of the V-shapedfurrow 60. The furrow 60 is then covered with soil and lightly compactedby the furrow closing assembly 40.

It should be appreciated that because seeds 62 fall freely through theseed tube 28 in the row unit 10 described above, the path of travel ofthe seeds and the velocity of the seeds at the exit of the seed tube arerelatively unconstrained. It would be preferable to constrain the pathof travel of seeds 62 in order to reduce errors in spacing betweenseeds; i.e., placing seeds in the field at non-uniform spacing.Additionally, it would be preferable to control the velocity of seeds 62such that the seeds have a decreased horizontal velocity relative to theground upon landing in the furrow 60.

Referring to FIGS. 2 through 4, a row unit 100 including a seed conveyor200 is illustrated. The row unit 100 preferably includes a gauge wheelassembly 130 and left and right opening discs 132 disposed to open aseed trench 60; a depth control assembly 180 preferably controls theheight of gauge wheels of the gauge wheel assembly 130 relative to theopening discs 132. The row unit 100 preferably includes a row unit frame120. The row unit frame preferably includes mounting pivots 117, 119 formounting the row unit frame 120 to a parallel arm arrangement. The rowunit frame 120 preferably includes a rear mount 141 for pivotallymounting a closing wheel assembly (not shown) configured to close theseed trench 60. The row unit frame 120 preferably includes adownwardly-extending shank 160 to which the opening discs 132 arerollingly mounted.

A seed meter 300 is mounted to the row unit frame 120. The seed meter300 is preferably driven by a motor 310 as disclosed in Applicant'sco-pending U.S. patent application Ser. No. 13/804,630 and Applicant'sco-pending International Patent Application No. PCT/US2013/051971 (“the'971 application”), the disclosures of both of which are incorporatedherein in their entirety by reference.

The seed conveyor 200 is preferably mounted to the row unit 100 asdisclosed in Applicant's co-pending International Patent Application No.PCT/US2012/057327 (“the '327 application”) and/or U.S. ProvisionalPatent Application No. 61/872319, the disclosures of both of which arehereby incorporated herein in their entirety by reference. A resilientseal 124 preferably seals a gap between the seed conveyor 200 and therow unit frame 120. The seed conveyor 200 is in seed communication withthe seed meter 300. The seed conveyor 200 is preferably driven by amotor 210. The motor 210 preferably comprises an electric motor operablycoupled to a gearbox. The motor 210 is preferably in electricalcommunication with and controlled by a control module 212.

Referring to FIG. 22, the seed conveyor 200 preferably includes a seedsensor 2200 disposed to detect passing seeds. The seed sensor 2200preferably comprises a transmitter 2210 configured to sendelectromagnetic energy (e.g. light) toward a receiver 2220. Asillustrated, the transmitter 2210 is preferably disposed to illuminate aregion through which seeds and flights pass, preferably through anopening 246 in a first sidewall of the conveyor cover 240. The sensor2200 is preferably disposed to detect seeds descending downward in theconveyor 200, e.g., adjacent to a forward portion of the belt 220. Thereceiver 2220 is preferably disposed in an opening 248 in an opposingsecond sidewall of the conveyor cover 240. Passing seeds 62 obstruct thelight transmitted to the receiver such that the receiver generates a“seed pulse”; the receiver is preferably in data communication with themonitor, which is preferably configured to process, time-stamp and storepulses. In preferred embodiments, the receiver 2220 includes a lens 2222(e.g. a quartz lens). In some embodiments the lens is coated with ahydrophobic coating. In some embodiments a portion of the receiver 2220(e.g., the lens 222 or a portion thereof) extends into the interior ofthe conveyor cover 240; in such embodiments, a wiper flight 223 (or aplurality of flights) is preferably disposed (e.g., by being slightlywider than the remaining flights) to contact the receiver 2220 (e.g.,the interior surface of the lens) in order to wipe foreign material fromthe receiver as the wiper flight passes the receiver. In someembodiments the transmitter may also include a lens (not shown) disposedto be contacted by one or more conveyor flights.

A protector 190 is preferably removably mounted to the shank 160. Arearwardly extending portion 192 of the protector 190 preferably extendsbetween a lower end of the seed conveyor 200 and the bottom of thetrench 60. The rearwardly extending portion 192 is thus disposed toprotect the seed conveyor 200 from contact with the bottom of the trench60 or other objects which may damage the seed conveyor. A lower surfaceof the rearwardly extending portion 192 is preferably disposed at aheight proximate the lower extent of the opener discs 132 such that theprotector 190 forms the bottom of the trench 60 in operation. In otherembodiments, the lower surface of the rearwardly extending portion 192is disposed at a height above (e.g., between 0.1 and 1 inches above) thelower extent of the opener discs such that the protector 190 ispositioned above and vertically adjacent to the bottom of the trench 60in operation. The protector 190 preferably includes inserts 194 disposedon either side of the protector; the inserts 194 are preferably disposedto guard the seed conveyor 200 from contact with the opening discs 132.The inserts 194 preferably comprise a relatively hard material such astungsten carbide, while the remainder of the protector 190 preferablycomprises a relatively tough metal.

A seed firmer assembly 170 is preferably mounted to the shank 160. Theseed firmer assembly 170 preferably includes a firmer bracket 172 and aseed firmer 174. The firmer bracket 172 preferably extends around theseed conveyor 200 and supports the seed firmer 174 rearward of the seedconveyor. The seed firmer 174 is preferably configured to press seedsinto the bottom of the trench 60; the seed firmer 174 preferablycomprises one of the seed firmer embodiments disclosed in U.S. Pat. No.7,497,174, the disclosure of which is hereby incorporated herein in itsentirety by reference.

Turning to FIG. 5, the seed conveyor 200 is illustrated in more detail.The seed conveyor 200 preferably includes a belt 220 including aplurality of flights 222 spaced to receive seeds. Each flight 222preferably includes a bevel 223 (see FIG. 6A); each bevel 223 preferablyfaces away from the direction of travel of the flight. The seed conveyor200 preferably includes a cover 240, preferably comprising a left-sideportion and a right-side portion; the left-side portion of the cover 240is removed in FIGS. 5, 6A and 6B in order to illustrate the belt 220.Referring to FIG. 6A, in operation seeds are conveyed down a forwardside of the belt 220 between the flights 222. Seeds are preferablyreleased from an opening 242 at a lower end of the cover 240. Seeds arepreferably released in a rearward trajectory (preferably guided by alower surface 244 of the cover 240); thus the seeds have a lowerhorizontal velocity relative to the trench 60 upon release from the seedconveyor 200 than when released from the seed meter 300.

Pulley Embodiments

Referring to FIGS. 5 and 7, the belt 220 is preferably operably coupledto an upper pulley 260 and a lower pulley 250 for conveyance about theupper pulley and the lower pulley. The upper pulley 260 is preferablyrotationally driven by the motor 210. Referring to FIG. 8, the upperpulley 260 preferably includes a plurality of radially arranged lugs 262configured to engage corresponding slots 226 formed in the belt 220between each flight 222. In operation, the upper pulley 260 preferablydrives the belt 220 by sequential engagement between the slots 226 andthe lugs 262. Each slot 226 preferably extends through the full width ofthe belt 220. Each lug 262 preferably extends through the belt 220 whenthe lug is engaged in the slot 226 such that an outer tip of the lugextends outside the belt.

Turning to FIG. 6A, a first detailed embodiment of a lower pulley 250′is illustrated. The lower pulley 250′ preferably comprises a radialouter surface 253 rigidly mounted to an inner wheel 254. The radialouter surface 253 preferably comprises a relatively rigid material suchas plastic. The radial outer surface 253 preferably includes a pluralityof radially arranged lugs 252 configured to engage corresponding slots226 formed in the belt 220. The inner wheel 254 preferably comprises arelatively elastic material such as rubber. The inner wheel 254preferably includes a plurality of spokes 255 radially arranged in aswept arrangement. The inner wheel 254 of the lower pulley 250′ ispreferably mounted to a bearing 256. The bearing 256 is preferablymounted to the cover 240 by a screw 258. When the spokes 255 are in arelaxed (undeflected) state, the radial outer surface 253 rotates abouta central axis of the bearing 256. Tension in the belt 220 imparts anupward force on the lower pulley 250′ such that the spokes 254 aredeflected and the radial outer surface 253 is deflected upward and theradial outer surface rotates about an axis above the central axis of thebearing 256. The tension in the belt 220 upon installation is preferablyselected such that the spokes 255 are preferably partially deflected;thus the rotational axis of the radial outer surface 253 is permitted tofloat upward and downward to retain consistent tension in the belt 220as components wear or deform over time. Thus the pulley 250′ isconfigured to deform to resiliently retain consistent belt tension.

Turning to FIG. 6B, a second detailed embodiment of a lower pulley 250″preferably comprises a relatively hard material such as plastic. In suchan embodiment, it should be appreciated that the lower pulley 250″ isunable to deform to compensate for changes in tension of the belt 220;thus in such an embodiment the lower pulley 250″ is preferablyresiliently mounted to the cover 240. In the illustrated embodiment, theseed conveyor 200 includes a spring mount assembly 280. The spring mount200 includes a sliding member 286 slidingly received in a cavity 288.The lower pulley 250″ is preferably rollingly mounted to the slidingmember 286 about a bearing 256. The bearing 256 is preferably mounted tothe sliding member by a screw 258. The belt 220 engages and imposes anupward force on the pulley 250″. The upward force imposed by the belt onthe pulley 250 is transmitted to the sliding member 286. The upwardforce on the sliding member 286 is preferably countered by downwardforce imposed on the sliding member 286 by a spring 284. The position ofspring 284 is preferably maintained by a pocket 282 in the cover 240 andby a rod 285 mounted to the sliding member 286. It should be appreciatedthat the downward force imposed by spring 284 increases as the lowerpulley 250″ is deflected upward. The spring 284 is preferably partiallydeflected upon installation of the belt 222 such that the lower pulley250″ is enabled to deflect or “float” upward and downward to retainconsistent tension in the belt 220.

Continuing to refer to FIG. 6B, a bolt 289 is preferably received by athreaded hole in the sliding member 286. The sliding member 286 may beselectively locked in a fixed position relative to the cavity 288 byadvancing the bolt 289 into contact with the cover 240. In someembodiments the sliding member 286 is locked in place upon installation(after the spring mount assembly 280 has reached an equilibrium state.In other embodiments the sliding member is allowed to move freely inoperation.

In an alternative conveyor embodiment 2300 illustrated in FIG. 23, a thebelt 220 is disposed to rotate about the upper pulley 260, the lowerpulley 250 and third pulley 2310. Flights 222 preferably pass the thirdpulley 2310 after passing the lower pulley 250 and before passing theupper pulley 260. The third pulley 2310 is preferably disposed at aheight lower than the upper pulley and higher than the lower pulley. Thecenter of the third pulley 2310 is preferably disposed rearward of anaxis defined by the centers of the upper pulley and the lower pulley.Flights 222 preferably accelerate when rounding the third pulley 2310.Thus the third pulley 2310 is preferably disposed to urge debris orliquid between the flights 222 away from the belt by centrifugal forceas the flights pass the third pulley.

Loading Wheel Assembly Embodiments

Referring to FIGS. 7 through 9, the seed conveyor 200 preferablyincludes a loading wheel assembly 400. The loading wheel assembly 400 ispreferably configured to remove seeds from the seed meter and transferthem to the seed conveyor 200.

A brief description of the operation of the seed meter 300 is helpful inorder to describe its cooperation with the seed conveyor 200,specifically the loading wheel assembly 400. The seed meter 300 includesa seed disc 320 having a plurality of radially arranged seed apertures322. As disclosed in more detail in the '971 application incorporated byreference above, the seed meter 300 is preferably configured to entraina seed on each seed aperture (preferably by imposing a vacuum on oneside of the apertures) and release the seed at a release point(preferably by cutting off the imposed vacuum), preferably approximatelythe 3 o'clock position as viewed along the perspective of FIG. 7. Theapertures 322 translate the seeds along a seed path. The seed path ispreferably a semi-circular path defined by the positions of theapertures 322. As viewed along the perspective of FIG. 7, seeds travelclockwise along the seed path.

The loading wheel assembly 400 is preferably configured to remove seedsfrom the seed disc 320 at a location along the seed path, preferablyprior to the release point. In the embodiment of FIG. 7, the loadingwheel assembly 400 includes a first loading wheel 410 and a secondloading wheel 420. The first loading wheel 410 and the second loadingwheel 420 are preferably disposed on opposite sides of the seed path.The first loading wheel 410 preferably has a smaller effectivecircumference than the second loading wheel 420. The loading wheels 410,420 are preferably driven for rotation about hubs 414, 424 by the motor210. The loading wheels 410, 420 are preferably driven in oppositerotational directions. As viewed along the perspective of FIG. 7, thefirst loading wheel 410 is driven for clockwise rotation and the secondloading wheel 420 is driven for counter-clockwise rotation. Inoperation, seeds passing through a gap between the loading wheels 410,420 are grasped between the loading wheels and ejected downward towardthe seed conveyor 200. As viewed along the perspective of FIG. 7, seedsenter the seed conveyor 200 above the upper pulley 260 and are conveyeddown the right-hand side of the seed conveyor. The gap between theloading wheels 410, 420 is preferably sized to grasp the seeds; e.g., insome embodiments the gap is slightly smaller than a minimum width of theseed.

In the embodiment of FIGS. 7-9, the seed disc 320 includes a singlearray of seed apertures 322 defining a seed path; the seed pathpreferably intersects a gap between the loading wheels 410, 420. Turningto FIG. 10, an alternative seed disc 320′ includes an outer array ofouter seed apertures 324 and an inner array of inner seed apertures 326.The outer array defines an outer seed path traveled by seeds entrainedon the outer seed apertures 324. The inner array defines an inner seedpath traveled by seeds entrained on the inner seed apertures 326. Theouter seed path preferably intersects the gap between the loading wheels410, 420. The inner seed path preferably intersects the first loadingwheel 410; seeds on the inner seed apertures 326 are guided by rotationof the first loading wheel 410 into the gap between the loading wheels410, 420.

An alternative loading wheel assembly 400′ illustrated in FIG. 24comprises the loading wheel 420 and a guide insert 2400 having a guidesurface 2410. The guide surface 2410 is preferably disposed to guideseeds on the seed apertures toward a gap 2420 between the guide surface2410 and the loading wheel 420. In operation, seeds enter the gap 2420,is preferably lightly compressed between the loading wheel 420 and thesurface 2410, and is then ejected into the belt 220 between the flights222, preferably forward of a vertical plane defined by the rotationalaxis of the upper pulley 260. As illustrated in FIG. 24, the alternativeloading wheel assembly 400′ is used in cooperation with the seed disc320′; however, it should be appreciated that the alternative loadingwheel assembly 400′ may be used in cooperation with other seed discssuch as the seed disc 320.

Returning to the embodiment of FIGS. 7-9, the loading wheels 410, 420include a plurality of circumferential fingers 412, 422, respectively.The fingers 412, 422 are preferably oriented in a direction opposite thedirection of rotation of their respective loading wheels 410, 420. Thusthe fingers 412, 422 are oriented in a backswept orientation. As bestillustrated in FIG. 8, each finger 422 of the second loading wheel 420preferably comprises three axially aligned fingers 422-1, 422-2, 422-3having axial gaps therebetween.

The fingers 412, 422 of the loading wheels 410, 420 are preferablyrotationally oriented in synchronized orientations; e.g., such that whena finger 412 is at its closest position to the central axis of theloading wheel 420, a corresponding finger 422 is at its closest positionto the central axis of the loading wheel 410. The motor 210 preferablydrives the loading wheels 410, 420 at synchronized rates (e.g., at thesame rate in terms of rotations per minute) such that the loading wheelsremain synchronized as described above during operation. In otherembodiments the fingers 412, 422 are oriented in unsynchronizedorientations.

Turning to FIG. 11, an alternative loading wheel assembly 500 preferablyincludes a first loading wheel 510 and a second loading wheel 520. Thefirst loading wheel 510 preferably includes an array ofcircumferentially arranged large dents 518 and an array ofcircumferentially arranged small dents 516. Each small dent 516 ispreferably disposed between two large dents 518 along the circumferenceof the first loading wheel 510. The second loading wheel 520 preferablyincludes an array of circumferentially arranged large dents 528 and anarray of circumferentially arranged small dents 526. Each small dent 526is preferably disposed between two large dents 528 along thecircumference of the second loading wheel 520. The second loading wheelpreferably includes axial gaps similar to the axial gaps in the secondloading wheel 420 for interacting with the guide 430 described below.

Guide Embodiments

Referring to FIGS. 7-9, the loading wheel assembly 400 preferablyincludes a guide 430. The guide 430 preferably includes a plurality oflaterally spaced fins 432-1, 432-2, 432-3. Fin 432-1 extends between thefingers 422-1 and 422-2 of the loading wheel 420. Fin 432-2 extendsbetween the fingers 422-2 and 422-3 of the loading wheel 420. Inoperation, as the loading wheel 420 rotates, the fingers 422-2 passbetween the fins 432-1 and 432-2. In operation, as the loading wheel 420rotates, the fingers 422-3 pass between the fins 432-2 and 432-3. Acurved inner surface of each fin 432 is preferably disposed such that aplane tangential to the curved inner surface extends between acircumference of the loading wheel 420 and a center of the loading wheel420. The guide 430 preferably comprises three substantially identicalportions 435. Each portion 435 preferably includes an arcuate surface436; the arcuate surface 436 is preferably concave with respect to seedstraveling into the seed conveyor 200. Each arcuate surface 436preferably terminates at an upper end at an angled surface 437. Theangled surface 437 of the portion 435-3 preferably extends between thefins 432-2, 432-3; and the angled surface 437 of the portion 435-2preferably extends between the fins 432-1, 432-2. The guide 430preferably comprises a relatively hard material such as metal andpreferably comprises powdered metal.

In operation, as seeds are communicated into the seed conveyor 200, thetrajectory of seeds ejected by the loading wheels 410, 420 tends tocause the seeds to contact the guide 430. As seeds contact the guide430, they are guided down the right-hand side of the seed conveyor 200(as viewed along the perspective of FIG. 7) by the fins 432 and thearcuate surfaces 436, respectively.

The loading wheel assembly 500 illustrated in FIG. 11 preferably alsoincludes a guide 430 that interacts with the second loading wheel 520 asdescribed above with respect to the second loading wheel 420.

Brush Embodiments

Turning to FIGS. 14 and 15, a guide brush assembly 1400 adjacent to theseed disc 320′ is illustrated. It should be appreciated that the guidebrush assembly 1400 may also be used in cooperation with the single-rowseed disc 320.

The guide brush assembly 1400 preferably includes an outer brush 1410and an inner brush 1420. The brushes 1410, 1420 are preferablypositioned adjacent to the seed disc 320′ and above the gap between theloading wheels 410, 420. The outer brush 1410 preferably comprises aclip 1412 securing a resilient bristle set 1414. The inner brush 1420preferably comprises a clip 1422 securing a resilient bristle set 1424.The brushes 1410, 1420 are preferably oriented such that the resilientbristle sets 1414, 1424 approach one another along the path traveled byseeds approaching the loading wheel assembly 400. The brushes 1410, 1420thus guide seeds into the gap between the loading wheels 410, 420.

The guide brush assembly 1400 preferably further includes a side brush1430. The side brush 1430 is preferably positioned adjacent to the seeddisc 320′ and above the gap between the loading wheels 410, 420. Theside brush 1430 preferably comprises a clip 1432 securing a resilientbristle set 1434. The side brush 1430 is preferably oriented such that alower end of the resilient bristle set 1434 is closer to the seed disc320′ than an upper end of the resilient bristle set 1434. As seedsentrained on apertures 324, 326 approach the loading wheel assembly 400,the side brush 1430 resiliently maintains contact between the seeds andthe seed disc 320′. The side brush 1430 preferably extends between theloading wheels 410, 420.

Vent Embodiments

Referring to FIGS. 12 and 13, the cover 240 preferably includes one ormore vents configured to allow debris or liquid to escape the interiorof the cover 240 during operation. Each vent is preferably located in areturn side of the cover 240, i.e., in a side of the cover 240 adjacentto the portion of the belt 220 that is returning from the lower portionof the conveyor 200 to an upper portion of the conveyor 200. In theillustrated embodiment, the rearward side of the cover 240 (i.e., theleft side as viewed along the perspective of FIG. 12) is the return sideof the cover. A first vent 270 preferably comprises an opening in both arearward and side surface of the cover 240. The first vent 270 ispreferably located adjacent to the lower sprocket 250. A surface 272preferably extends from an interior surface of the cover 240 through thevent 270 to allow debris or liquid to pass from the interior of thecover through the vent 270. A first side vent 295 is preferably formedin a side surface of the cover 240, preferably in the lower half of thecover 240. The cover 240 preferably includes a side vent (not shown) ina side surface of the cover 240 mirroring the first side vent 295. Aguide 297 (e.g., a v-shaped protrusion formed a rear inner surface ofthe cover 240) is preferably configured to guide debris or liquid towardthe side vent 295 and its minoring side vent. A second side vent 290 ispreferably formed in a side surface of the cover 240, preferablydisposed above the first side vent 295. The cover 240 preferablyincludes a side vent (not shown) in a side surface of the cover 240mirroring the second side vent 290. A guide 292 (e.g., a v-shapedprotrusion formed a rear inner surface of the cover 240) is preferablyconfigured to guide debris or liquid toward the side vent 290 and itsminoring side vent.

To further reduce build-up of debris or liquid within the conveyor, theinterior of the cover 240 preferably has a fine surface finish and insome embodiments is coated with a hydrophobic coating (e.g., manganeseoxide polystyrene or zinc oxide polystyrene nano-composite, precipitatedcalcium carbonate, or a silica nano-coating).

Alternative Meter-Conveyor Interface Embodiment

Turning to FIGS. 16-21, a modified embodiment of the row unit 200 isillustrated. Referring first to FIG. 10, the meter 300 preferablyincludes a pivot bar 1610 disposed to be pivotally mounted to the rowunit such that the seed meter is pivotable about the pivot bar. Theconveyor 200 is preferably mounted to the shank of the row unit via aspring 1620 which biases the conveyor upward. In an installation phase,the operator preferably first mounts the conveyor 200 in the positionillustrated in FIGS. 16 and 17 and then pivots the seed meter 300downward (clockwise on the view of FIG. 16) into engagement with theconveyor 200.

Referring to FIGS. 18-21, the conveyor motor 210 preferably includes ahousing 214 having a guide boss 1632. The seed meter preferably includesa seed side housing 340 having a guide pocket 1630. As the seed meter ispivoted into engagement with the conveyor, the guide boss 1632preferably enters the guide pocket 1630 and abuts an upper inner surfaceof the guide pocket. The seed side housing 340 preferably includes aflange 1634 for guiding the guide boss 1632 into the guide pocket 1630.When the guide boss 1632 abuts the guide pocket 1630, the spring 1620preferably biases the guide boss into abutment with the guide pocket,constraining the relative vertical position of the guide boss and theguide pocket. When the guide boss 1632 abuts the guide pocket 1630, aleft guide clip 1680a and a right guide clip 1680 b of the seed meter300 preferably slidingly engage a guide fin 280 of the conveyor 200,constraining the relative lateral position of the conveyor and the seedmeter. The seed side housing 340 preferably includes a curvilinearsurface 1636 and the housing 214 preferably includes a curvilinearsurface 1638; the surfaces 1636, 1638 preferably have substantiallyequal radii. The curvilinear surface 1636 preferably define s a centralaxis D such that when the meter and the conveyor are engaged, the meterand conveyor slide relative to one another about the axis D. Referringto FIG. 20, the guide boss 1632 preferably defines a central axis C.When the guide boss 1632 abuts the guide pocket 1630, the axes C, D arepreferably parallel and intersecting such that the guide boss 1632 andthe surface 1636 are coaxial. The surface 1638 and the guide boss 1632are preferably coaxial. Referring to FIG. 21, the axis D is preferablylocated at or immediately adjacent to the location where seed meter 300releases seeds, preferably between the loading wheels. Thus in theembodiment of FIGS. 16-21, when the seed meter 300 and the conveyor 200are engaged, the seed meter and conveyor pivot relative to one anotherabout a location at or immediately adjacent to the seed release point ofthe seed meter (e.g., the 3 o'clock position of the seed disc) andpreferably between the loading wheels.

Continuing to refer to the embodiment of FIGS. 16-21, the seed meter 300preferably includes a housing 375 having a screen vent 375. The screenvent 375 is preferably in fluid communication with an interior volume ofthe seed side housing 340. Thus air may be drawn through the screen vent375 into the seed side housing 340 by vacuum imposed on a vacuum sidehousing 330 of the seed meter via a vacuum inlet 334. The seed sidehousing 340 preferably includes a seed inlet 342 in seed communicationwith a seed hopper 344 mounted to the seed side housing.

Seed Velocity Control

In some embodiments, the conveyor motor may drive the conveyor belt at aconstant speed. In other embodiments, the conveyor belt may be driven ata speed directly related to the operational speed of the seed meter; insome such embodiments, the conveyor motor may be driven. However, asdisclosed in the '327 application previously incorporated by referenceherein, the conveyor motor 210 is preferably in data communication witha monitor configured to control the operating speed of the conveyormotor and thus the velocity of seeds exiting the seed conveyor into thetrench. In such embodiments, described in further detail below, theconveyor belt is preferably driven at an operating speed directlyrelated to the ground speed S of the conveyor. The ground speed S may beestimated based on the implement speed or a row-specific speed may bedetermined as disclosed in the '327 application. As used herein, therelease velocity V of the seed refers to the velocity of the seed uponrelease along the travel direction of the seed upon release, at an angleθ below horizontal. The release velocity V of the seed may be determinedbased on the rotational speed R of the conveyor motor by the relationV=CR, where C is a constant.

In one embodiment, the conveyor belt is driven at a multiple of theconveyor ground speed, where the multiplier is determined based on theangle of release of seed from the conveyor, e.g. to match the horizontalvelocity of the seed to the ground speed. As an example, if the seed isreleased from the conveyor at 45 degrees below horizontal, then therotational speed R is preferably selected by the monitor using therelation:

$R = \frac{S}{C\; \cos \; \theta}$

In similar embodiments, a nominal rotational speed R may be determined(e.g., as described above) and a modified rotational speed R_(m) may becommanded to the motor, where the modified rotational speed is modifiedby a geometric gain A and an arithmetic gain B according to therelation:

R _(m) =AR+B

The gain values A and B may be selected empirically in order to improvein-field spacing. In some embodiments an in-trench seed sensor such asthat disclosed in U.S. Pat. No. 8,418,636, incorporated by reference,may be used to determine an in-trench spacing value. In some suchembodiments, the gain values of A and B may be iteratively modified inorder to improve the in-trench spacing. As an example, the value of Bmay be increased by a predetermined increment and the monitor determineswhether the in-trench spacing value increases; if the in-trench spacingvalue increases after the value of B is increased, then the monitorpreferably again increases the value of B by the predetermined incrementand then again determines whether the in-trench spacing value hasincreased. If the in-trench spacing value stops increasing or decreaseswith increased values of B, then the monitor preferably stops theiterative gain modification. In some embodiments, the in-trench spacingvalue may be determined using the relations (e.g. the relations used tocalculate the “Good Spacing Value”) disclosed in U.S. Pat. No.8,386,137, but preferably using in-trench seed sensor pulse times ratherthan seed tube seed sensor pulse times to determine spacing values.

The foregoing description is presented to enable one of ordinary skillin the art to make and use the invention and is provided in the contextof a patent application and its requirements. Various modifications tothe preferred embodiment of the apparatus, and the general principlesand features of the system and methods described herein will be readilyapparent to those of skill in the art. Thus, the present invention isnot to be limited to the embodiments of the apparatus, system andmethods described above and illustrated in the drawing figures, but isto be accorded the widest scope consistent with the spirit and scope ofthe appended claims.

1. An apparatus for delivering seed to a planting surface, comprising: aseed meter configured to entrain and release the seed from a seed discat a seed release location; a seed conveyor disposed to receive the seedafter the seed is released from said seed disc at an upper end of saidseed conveyor, said seed conveyor having a belt configured to convey theseed from said upper end to a lower end of said seed conveyor, whereuponthe seed is discharged from said seed conveyor through an opening, saiddischarged seed having a rearward velocity relative to said seedconveyor, said seed conveyor having a cover; at least one vent in saidcover disposed adjacent to a return portion wherein said belt travelsfrom said lower end of said seed conveyor to said upper end of said seedconveyor.
 2. The apparatus of claim 1, wherein said at least one vent isdisposed adjacent to a lower sprocket in said seed conveyor.
 3. Theapparatus of claim 1, wherein said at least one vent comprises anopening in both a rearward surface and a side surface of said cover. 4.The apparatus of claim 1, wherein said at least one vent comprises asurface that extends from an interior surface of said cover through saidvent.
 5. The apparatus of claim 1, wherein said at least one ventincludes a first side vent disposed in a side of said cover.
 6. Theapparatus of claim 5, wherein said first side vent is disposed in alower half of said seed conveyor.
 7. The apparatus of claim 5, whereinsaid at least one vent includes a first mirroring side vent disposed ina side of said cover mirroring said first side vent.
 8. The apparatus ofclaim 5, further comprising: a guide disposed on a rear inner surface ofsaid cover, said guide configured to guide at least one of debris andliquid toward said first side vent.
 9. The apparatus of claim 7, furthercomprising: a guide disposed on a rear inner surface of said cover, saidguide configured to guide at least one of debris and liquid toward saidfirst side vent and said first mirroring side vent.
 10. The apparatus ofclaim 5, wherein said at least one vent includes a second side ventdisposed in a side of said cover above said first side vent.
 11. Theapparatus of claim 10, wherein said at least one vent includes a secondmirroring side vent disposed in a side of said cover mirroring saidsecond side vent.
 12. The apparatus of claim 10, further comprising: aguide disposed on a rear inner surface of said cover and configured toguide at least one of debris and liquid toward said second side vent.13. The apparatus of claim 7, further comprising: a guide disposed on arear inner surface of said cover and configured to guide at least one ofdebris and liquid toward said second side vent and said second mirroringside vent.
 14. The apparatus of claim 1, wherein said at least one ventcomprises: a first side vent disposed in a side of said cover in a lowerhalf of said seed conveyor; a first mirroring side vent disposed in aside of said cover mirroring said first side vent; a first guidedisposed on a rear inner surface of said cover and configured to guideat least one of debris and liquid toward said first side vent and saidfirst mirroring side vent; a second side vent disposed in a side of saidcover above said first side vent; a second mirroring side vent disposedin a side of said cover mirroring said second side vent; and a secondguide disposed on a rear inner surface of said cover and configured toguide at least one of debris and liquid toward said second side vent andsaid second mirroring side vent.
 15. The apparatus of claim 1, furthercomprising: a first loading wheel disposed adjacent to said seed releaselocation, said first loading wheel being driven for rotation, whereinsaid first loading wheel compresses the seed against an opposingsurface, and wherein said first loading wheel ejects the seed towardsaid seed conveyor.